Convert ticks from hardware timestamp

When getting the hardware timestamp, the higher resolution part is measured
in ticks and a conversion based on the nominal clocks is done to convert
to user units

config_d/registers

@@ -42,7 +42,7 @@ BLOCKS_COMPAT_VERSION = 0
 
     # Hardware timestamps
     PCAP_TS_SEC             10
-    PCAP_TS_NSEC            11
+    PCAP_TS_TICKS           11
 
     # Position capture control
     PCAP_ARM                13

server/data_server.c

@@ -118,15 +118,16 @@ static void update_start_timestamp(void)
     struct timespec pcap_drv_start_ts, pcap_hw_start_ts;
     hw_get_start_ts(&pcap_drv_start_ts);
     hw_get_hw_start_ts(&pcap_hw_start_ts);
-    if (pcap_hw_start_ts.tv_sec == 0 && pcap_hw_start_ts.tv_nsec == 0) {
+    if (pcap_hw_start_ts.tv_sec == 0 && pcap_hw_start_ts.tv_nsec == 0)
+    {
         pcap_start_ts = pcap_drv_start_ts;
         pcap_hw_ts_offset_ns_valid = false;
-    } else {
-        int64_t drv_ts_num =
-            (int64_t) pcap_drv_start_ts.tv_sec * 1000000000
+    }
+    else
+    {
+        int64_t drv_ts_num = (int64_t) pcap_drv_start_ts.tv_sec * NSECS
             + pcap_drv_start_ts.tv_nsec;
-        int64_t hw_ts_num =
-            (int64_t) pcap_hw_start_ts.tv_sec * 1000000000
+        int64_t hw_ts_num = (int64_t) pcap_hw_start_ts.tv_sec * NSECS
             + pcap_hw_start_ts.tv_nsec;
         pcap_start_ts = pcap_hw_start_ts;
         pcap_hw_ts_offset_ns = drv_ts_num - hw_ts_num;

server/hardware.c

@@ -328,7 +328,10 @@ void hw_get_start_ts(struct timespec *ts)
 void hw_get_hw_start_ts(struct timespec *ts)
 {
     ts->tv_sec = (time_t) read_named_register(PCAP_TS_SEC);
-    ts->tv_nsec = (typeof(ts->tv_nsec)) read_named_register(PCAP_TS_NSEC);
+    ts->tv_nsec = (typeof(ts->tv_nsec)) ((uint64_t)
+        read_named_register(PCAP_TS_TICKS) * NSECS / hw_read_nominal_clock());
+    ts->tv_sec += ts->tv_nsec / NSECS;
+    ts->tv_nsec = ts->tv_nsec % NSECS;
 }
 
 #endif